Energy Transformations
What is the energy transformation that occurs when you eat food?
What is ... chemical energy to mechanical energy/kinetic energy
Alan launches a ball of clay into the air using a catapult. He calculates its kinetic energy to be 9.0 J. He then launches a ball with half the mass of the first ball. He launches the smaller ball into the air at the same speed. What is the kinetic energy of the smaller ball?
A. 3.0 J
B. 4.5 J
C. 9.0 J
What is ... 4.5 J
If a 8th grade student eats a pancake for breakfast and then walks to school. What form of energy was the pancake?
What is ... Chemical Energy
_____________ is the transfer of energy to or from or object via the application of a force along a displacement.
What is ... work
Electrical energy can be produced from ...
A. mechanical energy
B. chemical energy
C. radiant energy
D. all of the above
What is ... D, all of the above
Explain the energy transformations that occurs when you turn an electric fan on?
What is ... electrical energy to mechanical energy (maybe some sound energy)
A 1.5 kg bowling ball rolls down a lane at a speed of 9 m/s.
What is the kinetic energy of the bowling ball?
The formula is KE = 1/2 mv2
What is ... 60.75 J
If you are riding a roller coaster what form of energy increases as you go up the roller coaster?
What is ... potential/gravitational potential energy
A person moves a ball up a ramp. Which statement describes this process?
A. There is a transfer of energy, and work is done.
B. There is no transfer of energy, but work is done.
C. There is a transfer of energy, but no work is done.
What is ... A, there is a transfer of energy, and work is done
Electricity is the movement of ...
A. atoms
B. molecules
C. electrons
D. neutrons
What is ... C, electrons
What energy transformation occurs within a waterfall?
What is ... potential energy to kinetic energy
A 2 kg toolbox is lifted from the floor up to a shelf that is 3 meters high. (Use g = 10 m/s²). How much gravitational potential energy does the toolbox gain?
The formula is Gravitational Potential Energy = mass x gravity x height (PE = mgh)
What is ... 60 Joules
PE = 2 kg x 10 m/s2 x 3m
What is ... sound energy/mechanical energy/kinetic energy
TRUE or FALSE: When you push your hands together and rub them back and forth rapidly, your muscles are doing work.
Bonus! What energy transformation is happening?
What is ... True
Bonus: What is mechanical/kinetic energy to thermal energy
Solar, biomass, geothermal, wind, and hydropower energy are all renewable sources of energy. They are called renewable because they ...
A. are clean and free to use
B. can be converted directly into heat and electricity
C. can be replenished by nature in a short period of time
D. do not produce air pollution
What is ... C, can be replenished by nature in a short period of time
Explain the energy transformation of photosynthesis in plants?
What is ... light energy to chemical energy/stored chemical energy
In a local competition, students race model cars that they built. The cars were held still at the top of a ramp and then released. Each car’s velocity was measured at the bottom of the ramp to calculate each car’s kinetic energy.
Model Car Trials
Model Car # Kinetic Energy
1 14 Joules
2 13 Joules
3 16 Joules
Based on the data in the table, which of these could be the potential energy of Car 2 at the top of the hill?
A. 6 Joules
B. 12 Joules
C. 15 Joules
What is ... C, 15 Joules
~Potential Energy is always greater than or the same as the kinetic energy
Liquid particles in a boiling beaker begin to move faster and collide violently, causing an increase in temperature that flows from a hot stove burner to a cold metal pot.
What is ... Thermal Energy
A carpenter leaves several tools on the floor of his workshop when he goes for his lunch break. Sometime later the carpenter returns and sees that one of his coworkers has moved his tools to different shelves on a nearby bookshelf.
Which data would the carpenter need to collect to calculate the amount of work required to lift his tools onto the shelves? (there is more than one correct answer)
A. the height of each shelf
B. the time it took to move each tool
C. the amount of force needed to lift each tool
What is ... A and C
The carpenter needs to measure the height of each shelf as well as the amount of force needed to lift each tool.
At which point on a roller coaster does a cart have the maximum gravitational potential energy?
A. at the very top of the highest hill
B. at the very bottom of the steepest drop
C. halfway up the first hill, moving fast
D. when it comes to a complete stop at the unloading station on flat ground
What is ... chemical energy to electrical energy.
~the battery of a mobile phone contains chemical energy.
It can then be converted to light, sound, and heat energy.
A 1 kg ball is thrown straight up into the air and its height is recorded every second until it reaches the ground a little more than 3 seconds later. The height of the ball above the ground is shown in the table. What is the potential energy of the ball at each time? Gravitational potential energy can be calculated by multiplying the mass, the height, and the acceleration due to gravity (9.8 m/s2). Acceleration due to gravity can be rounded to 10 m/s2. Calculate the gravitational potential energy for the with the information below.
Time (s) Height (m)
0 0
1 8
2 10
3 3
What is ...
Gravitational Potential Energy:
0 J
80 J
100 J
30 J
Reactors use uranium-235 fuel to split atoms (nuclear fission), creating heat that boils water into steam to turn turbines. What form of energy is the uranium-235?
What is ... Nuclear energy
A person pushes a box with a force of 5 N across a smooth floor, moving it a distance of 2 m in the same direction. Calculate the work done by pushing the box.
Work = force x distance or W = F x d
What is ... 10 J
What is typically the very first step engineers take when beginning the engineering design process?
A. defining the problems and identifying constraints
B. building the final commercial product
C. advertising the product to the public
D. disassembling competitors'' items for parts
What is ... A. defining the problems and identifying constraints